Practice
Coin Flip Stop Rule
Solve step by step: reveal hints only when needed, then check your reasoning against the full walkthrough.
Problem set
Sample Variance by HandAnnualized Sharpe from Daily StatsConvert Covariance to CorrelationInterpret a Z-Score ShockTwo-Asset Portfolio VariancePosition Size from Risk BudgetKelly Fraction ScenarioInterpret Daily VaRTriangular FX Arbitrage CheckSharpe vs Sortino in Allocation ChoiceDice Game Expected ValueBoth Assets Down ProbabilityCoin Flip Stop RuleCard Draw: Ace then KingMonty Hall VariantCode: Rolling Sharpe (63-day)Code: Kelly Fraction FunctionCode: Max DrawdownCode: Historical VaR (95%)Code: Equal-Weight Rebalance Shares
PuzzleAdvanced
You flip a fair coin until first Heads.
You gain $2^k if first Heads occurs on flip k, but pay a $2 entry fee up front.
What is the expected net payoff: finite value or unbounded?
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